Process for depositing a layer of material on a substrate

Abstract

An electroplating system ( 30 ) and process makes electrical current density across a semiconductor device substrate ( 20 ) surface more uniform during plating to allow for a more uniform or tailored deposition of a conductive material. The electrical current density modifiers ( 364 and 37 ) reduce the electrical current density near the edge of the substrate ( 20 ). By reducing the current density near the edge of the substrate ( 20 ), the plating becomes more uniform or can be tailored so that slightly more material is plated near the center of the substrate ( 20 ). The system can also be modified so that the material that plates on electrical current density modifier portions ( 364 ) of structures ( 36 ) can be removed without having to disassemble any portion of the head ( 35 ) or otherwise remove the structures ( 36 ) from the system. This in-situ cleaning reduces the amount of equipment downtime, increases equipment lifetime, and reduces particle counts.

1. A process for depositing a layer of material over a semiconductor substrate comprising the steps of:
 placing the semiconductor substrate into a plating system, wherein the plating system includes:
 an anode; 
 a cathode that includes clamp structures for holding a semiconductor substrate; 
 an ionic liquid within a cup, wherein the ionic liquid contacts the anode, the semiconductor substrate, and the clamp structures; 
 
 depositing a layer of plating material onto the semiconductor substrate and the clamp structures; 
 removing the semiconducter substrate from the plating system; and 
 subsequent to removal of the semiconductor substrate from the plating system and prior to plating an additional semiconductor substrate, removing at least a portion of the plating material deposited on the clamping structures by in-situ cleaning, wherein in-situ cleaning includes biasing the cathode at a more positive potential than the anode in the absence of the semiconductor substrate. 
 
     
     
       2. A process for depositing a layer of material over a semiconductor substrate comprising the steps of:
 placing the semiconductor substrate into a plating system, wherein the plating system includes:
 an anode; 
 a cathode that includes clamp structures for holding a semiconductor substrate; 
 an ionic liquid within a cup, wherein the ionic liquid contacts the anode, the semiconductor substrate, and the clamp structures; 
 a diffuser located within the cup and positioned between the anode and the cathode; and 
 an electrical current density modifier being located with in the cup and positioned between the diffuser and a top of the cup; 
 
 depositing a layer of plating material onto the semiconductor substrate and the clamp structures; 
 removing the semiconductor substrate from the plating system; and 
 subsequent to removal of the semiconductor substrate from the plating system and prior to plating an additional semiconductor substrate, removing at least a portion of the plating material deposited on the clamping structures by in-situ cleaning, wherein in-situ cleaning includes biasing the cathode at a more positive potential than the electrical current density modifier, in the absence of the semiconductor substrate. 
 
     
     
       3. The process of  claim 2 , further comprising electrically floating the anode during removing at least a portion of the plating material deposited on the clamping structures. 
     
     
       4. The process of  claim 2 , further comprising not electrically floating the anode during removing at least a portion of the plating material deposited on the clamping structures. 
     
     
       5. The process of  claim 4 , further comprising conditioning the anode prior to processing additional substrates within the plating system.